Around 275,000 payments likely to total hundreds of millions of pounds have been held up by a glitch in HSBC's systems.
The fault has left many workers fuming as their salary simply has not arrived, leaving them potentially short of funds - just in time for the Bank holiday weekend.
While the problem does not relate to payments from banks other than HSBC, their customers will be affected by not receiving money that they expected to have been paid.
Alan Charlesworth, managing director of insurance and legal recruiter IPS Group, took to Twitter to complain: "None of my staff have been paid. HSBC when will this be sorted?"
Another Twitter user wrote: "HSBC. None of my staff have been paid. Cannot get through to them on the phone. Absolute shambles of a bank! Extremely poor performance.
"I trust you are going to reimburse my employees that will incur late payment fees due to your Bacs payments failure."
Also on Twitter, one user wrote: "Bacs payment system down on payday and before Bank Holiday. Lovely."
Lydia Smith tweeted: "HSBC UK where's my money? I didn't get paid my wages today and I have bills to pay."
HSBC said it was working to resolve the problem, but it still did not know whether it would be able to process the payments by the end of the day.
A spokesman said: "There has been a fault in the information used to process some payments from HSBC business customers.
"Approximately 275,000 payments have been affected, including payments to customers of other banks.
"HSBC apologises for the inconvenience this has caused. We are taking immediate steps to ensure the payments reach beneficiaries as quickly as possible.
"We will work with other banks to ensure that customers do not lose out as a result of today's problems."
The fault affecting payments relates to the way HSBC transmitted information to the national Bacs payment system.
It centred on payments such as invoices and salaries which should have gone out automatically overnight.
That means the number affected is not rising as it is not a problem affecting ongoing transfers today.
HSBC will work with other banks to make sure that, for example, should an account holder not receive their salary as a result of the problem but still makes a regular direct debit payment and goes into an overdraft, he or she would not lose out.
The Bank of England has been alerted over the glitch while the Financial Conduct Authority (FCA) said it would ensure the bank took steps to help those left at a disadvantage.
Bacs processes transactions worth up to around £50 billion every day and is seen as critical to the functioning of the UK financial system.
It said: "Bacs is aware of an isolated issue affecting one of its member organisations. The Bacs system is operating as normal and we are currently working with our partners to help resolve this as quickly as possible."
The Bank of England said: "We are in contact with HSBC regarding their recent IT issue. We will be working closely with HSBC as it resolves the problem."
An FCA spokeswoman said: "The FCA is in contact with HSBC regarding the issue.
"We will be working closely with the firm as it resolves the problem and to ensure there are steps in place to help consumers who are affected."
Richard Lloyd, executive director of consumer group Which?, said: "Banks have suffered a series of unacceptable failures with their IT systems in recent years and this latest one at HSBC will do little to reassure consumers that banks are making improvements.
"It's essential regulators continue to take tough action to ensure banks properly maintain the payments system we all rely on, and we expect HSBC to fully compensate anyone affected."